Cellulose-ether solvent and composition



Patented @ct. l7, llSZZQ unites STATES insane RAY L. STlNCHFIELD, OF ROCHESTER, NEW YORK, ASSIGNOR T EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

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No Drawing.

To all whomit may concern:

Be it known that I, RAY L. S'r'morrrmw a citizen of the United States of America-,-

tions produced by the aid of such solvents. A

One object of my invention is to provide a solvent which Wlll dissolve such large proportions of cellulose ethers thatthick or viscous flowable solutions may be obtained for use in plastic and film making arts. Another object of my invention is to provide a cellulose ether solution which may be manufactured into strong, flexible transparent film on the machines and by the methods now in use. a

In US. Patent No. 1,188,376, Lilienfeld,

June 20, 1916, there are disclosed a series of Certain of these alkyl ethers of cellulose. are practically insoluble in water, and my invention relates but is not limited to theethers having that property. While the others form thin solutions in the lower monohydroxy aliphatic alcohols, it has been found that such solvents by themselves will not. dissolve a suliicient proportion of the others to make a desirably thick flowable composition or' dop'e, such as may be used in the manufacture of photographic film base by the customary methods, or in the other plastic arts. 1

l have discovered that an adequately strong and useful solvent may be prepared by mixing one or more of the lower monohydroxy' aliphatic'alcohols with tetrachloroethane (CHCh-CHCIQ. While the proportions may vary widely, l find a useful range to be, by Way of illustration, 80 to 3 partsof the monohydroxy aliphatic alcohol and 20 to 97 parts by weight of tetrachloroethane. When the alcohol is above 80% of the mixture and sufficient cellulose ether is dissolved therein, there may be obtained, instead of a flowable film-forming composition a mixture which is useful for moulding and similar plastic manipulations.

While the amount of cellulose ether dissolved in my compound solvents may vary Application filed March 19, 1921. Serial No. 453,721.

considerably, it is noted, by way ofillustration, that 10 parts of water-insoluble ethyl cellulose dissolved in a mixture of 45 parts by weight of tetrachloroethane and 15 parts of methyl alcohol yields a fiowable filmforming composition. As a further illustration, it is noted that a viscous film-forming composition, suitable for use in the customary machinery, can be made by dissolving 10 parts of water-insoluble ethyl cellulose in 30 parts of tetrachloro'ethane and 30 parts of ethyl alcohol. When the film is formed, the alcohol evaporates much more rapidly than the tetrachloroethane, and the latter remains in considerable quantities in the film, imparting useful bustibility of the cellulose ether-film but it adds additional supplenem to the latter. The alcohols tend to avoid pitting or wrinkling of the film, due to their co-operation with the, less volatile tetrachloroethane. Moreover, they hasten the setting of the film in the standard film-manufacturing machinery.

The ingredients are of the ordinary commercial type, sufliciently purified for the process of lm manufacture, so as to give a dope yielding films havin the proper relative freedom from color; dlll'hile ll prefer to employ methyl or ethyl alcohol, or a mixture of them, the other lower monohydroxy aliphatic alcohols, isopro yl alcohol, prop 1 alcohol, butyl alcohol normal, iso an secondar and fusel oil are also useful to a consi erahle degree in connection with tetrachloroethane.

Having thus described my invention, what ll claim as new and desire to secure by Letters Patent is:

1. A compound solvent for others of cellulose, comprising a mixture of tetra-chloroethane and a lower monohydroxy aliphatic alcohol.

2. A compound solvent for alkyl ethers of cellulose, comprising from 97 to 20 parts of tetrachloroethane and 3 to 80 parts of a lower monohydroxy aliphatic alcohol.

3. A compound solvent for water-insoluble alkyl cellulose, com rising tetrachloroethane and methyl alcohol.

4. A viscous composition com rising a strong solution of alkyl ether of cellhlose in a mixture of tetrachloroethane and a lower monohydroxy aliphatic alcohol.

i roperties to it. Not only does 1t tend to' iminish even the small com- 97 to 20 parts by Weight of tetrachloro 5 ethane and 3 to 80 parts by weight of a lower monohydroxy aliphatic alcohol.

6v A composition of mattercomprising 10 parts of Water-insoluble ethyl cellulose and lvent containing approxi a compound so mately 4:5 parts of tetrachloroethane and 15 parts of inethyl alcohol. p

7. A composition of matter comprising an ether of cellulose dissolved in tetrachlorovethane and a co-solvent.

Signed at Roehester Newi York, this 16th day of'March, 1921;

RAYYL. STINCHFIELD. 

